Method and means for renewing ink-repellent surfaces on mercury printing plates



H. RENCK METHOD AND MEANS FOR RENEWING INKREPELLENT SURFACES ON MERCURY PRINTING PLATES Drigina; Filed Feb. 15-. 1930 Nov. 29,, 1932.

- Patented Nov. 29, 1932 UNITED STATES PATENT OFFICE HEINRICH RENCK, OF HAMBURG, GERMANY METHOD MEANS FOR BENEWING INK-REPELLENT SURFACES ON umcunv PBINTIN G PLATES Original application file d February 15,1930, Serial No. 428,723, and in Germany November 26, 1929.

- Divided and this application filed May 5, 1931. Serial No. 535,272.

application, filed February 15, 1930, Serial #428,723, of which the present application is a. division. I

In connection with mercury printing plates, it is well understood that the material of the ink-repelling parts of the plate must be renewed from time to time, for the reason that the ink-repelling mercury'or amalgam is gradually used up, especially if the plate is subjected to any extended, continuous printing use.

To provide for such renewal, it has been heretofore proposed to produce a combina:

tion, in the nature of a stable chemical compound, between the mercury in the shape of an emulsion and the printing ink. This method has proven unsatisfactory, for the reasonv that the compound is so firm in the combination of the mercury, emulsion and ink as to cause'some mercury and ink to be 'deposited on the metal plates during the printing process, thus rendering it impossible to secure prints whose ground surfaces are pure white. Furthermore, under these conditions the ink used for printing was bound to contain some mercury atoms owing to the emulsive properties of the latter, so that the printed matter was undesirable from a hygienic point of view.

Other lmown methods proposed the addition of metallic mercury to the ink previous to the printing process. These methods were also generally unsatisfactory by reason of the fact that the metallic mercury, by reason 40 of its weight, formed into small globules which prevented uniform precipitation of the amalgam when the mercury-contaminated ink was spread over the printing plate and thus formed a highly undesirable, imperfect ink-repelling area. I

The method of the present sists in atomizing the mercury by means of usual or special appliances and adding the atomized mercury to the ink while the printing process is proceeding. The atomized invention conmercury is applied to one of the revolving rollers or cylinders covered with ordinary printers ink in such a manner that the minute mercury atoms deposit themselves on the surface of the ink. This method has two distinct advantages, first in preventing the conglomeration of the mercury andthe formation of globules by reason of the speed at which the rollers are rotating, and second in insuring incident to the minute atomization of the mercury that the printing surface to be covered is treated with a uniform coating of amalgam.

A further object of the invention is the utilization in the method described of rollers formed with a slightly granular surface to insure that the mercury will cling to the rollers for a considerable period during the process of printing, and alsothat any superfluous mercury will collect in the small depressions of the roller surface.

Furthermore, the method lends itself to the use of a special mercury applying roller as distinguished from a printing roller.

As an illustration of the means for carrying out the method, in the accompanying drawing I Figure 1 illustrates the printing use of the mercury plates defined in the companion application above referred to, with the renewal of the mercury amalgam according to the method of the present application;

' Figure 2 is a plan view of one of the inking rollers;

Figure 3 is a view similar' to Figure 1 showing a modified mercury applying roller.

The printing plates. indicated at 1, are Socured by the rotary drum 2. and the ink is transferred to these plates through the medium of inking rollers, indicated at 3. These inking rollers have a surface which is slightly granular, as shown at 4 in Figure 2, and mercury in a finely atomized form is applied to one of these rollers by aspraying device G of special appropriate form to deliver the atomized mercury onto the surface of the inking roller in finely a'lomized form.

In the modification illustrated in Figure the mercury in finely atomized form is applied by a spraying device G to a roller E,

' as an inking roller or as a special roller shown with the said roller E of a slightly-granular surface form but free of ink.

In both the preferred and modified forms, the mercury is transferred to the surface of the roller in finely atomized form and either with the ink in the form shown in Figure 1 or independently of the ink-in the form shown in Figure 2 is applied to the plate for even amalgamation of the ink-repellent surfaces thereon so that such ink-repelling surfaces are continually renewed during the printing operation to insure the most efiective use of the mercury printing plates even when in long continuous use, as in printing large editions of a newspaper or the like.

The granular surfaces of the rollers, either in the modified form, serve to permit the collection in small depressions 0n the roller surface of the superfluous mercury, which is thus prevented from being delivered onto the plates in globular form. Of course, the speed of rotation of the rollers, either the inking roll orthe special roll, tends in a-very considerable degree to prevent the collection of the metallic mercury into globular form. Thus, the deposit of the mercury on the inkrepelling surfaces will be substantially uniform, and either when delivered direct from the special roller or with the ink from the inking roller there is an even delivery over the printing plate of the mercury incident particularly to its finely atomized form and tothe herein described method of applying it to the plates.

I claim 1. A method of renewing the mercury to the ink-repellent parts of mercury printing plates during the use of such plates in printing consisting in delivering the mercury in finely atomized form to the surface of a noninking roller operating in contact with the plate.

2. A method of renewing the mercury to the ink-repellent parts of mercury printing plates during the use of such plates in printing consisting in delivering the mercury in finely atomized form to the surface of a noninking roller.

3. A method of renewing the mercury to the ink-repellent parts of mercury printing plates during the use of such plates in printing consisting in delivering the mercury in finely atomized form to a roller having a slightly granular surface.

4. A means for renewing mercury to mercury printing plates during the printing operation comprising an ink-free roller operating in contact with the printing plate, and a spraying device for delivering mercury in finely atomized form onto the surface of the roller.

A means for renewing mercury to mercury printing plates during the printing operation comprising a roller operating in con- HEINRICH RENCK. [L. s.] 

